Paradox Community
Search:

 Welcome |  What is Paradox |  Paradox Folk |  Paradox Solutions |
 Interactive Paradox |  Paradox Programming |  Internet/Intranet Development |
 Support Options |  Classified Ads |  Wish List |  Submissions 


Paradox Newsgroups  |  Paradox Web Sites  |  Paradox Book List  |  FAQs From The Corel FAQ Newsgroup  



Subject: FAQ:PdoxDOS:Text Full FAQ 2001.02.05

Version 1.0 (1999.06.30)
        first collected by Laurie McIntosh
        edited by Mike Irwin, Lance Leonard,
        Laurie McIntosh, and Kasey Chang
        Thanks to Steve Green.
Version 1.1 (2001.02.05)
        Reposted by Mike Irwin
Repost by Mike Irwin: 2001.05.25

Please note: this is the first release of the FAQ. 
Mistakes are expected, and some sections are still 
missing. Please send in all the corrections or additions 
you feel like! Also, if any comments here are yours, 
please tell us so we can properly attribute it, thanks! 
--the editors

--BEGIN TABLE OF CONTENTS—

0 Introduction

1 What is Paradox for DOS?
2 Top X questions
3 General Paradox Questions
4 Table Questions
5 Forms and Reports Question
6 PAL Questions
7 Network and Multi-user Questions
8 Misc. Questions
9 Troubleshooting

--END TABLE OF CONTENTS--

====================
1 What is Paradox?
====================

Paradox is one of the most powerful and yet affordable
relational databases you can buy. Its chief competitors 
were Borland's dBase, Microsoft FoxBase and FoxPro, plus 
the dBase compilers such as WordTech & Clipper.

--------------------
 1.1 Paradox History
--------------------

Paradox started out as a DOS program by Ansa Corporation.
They designed Paradox 1.0 and 2.0. Later Ansa was absorbed
by Borland, who produced 3.0, 3.5, 4.0, and 4.5, steadily
adding more and more powerful features. 4.0 saw the change
to the CUA-type windowed interface instead of the 
Lotus-type interface of 3.X.

Current version is V4.5 for DOS, the final version.

------------------------
 1.2 System Requirements
------------------------

Paradox for DOS only requires a 286 with 640K of RAM to 
run, though it can use up to 16 Megs of XMS.

--------------------
 1.3 Version History
--------------------

1.0
2.0
3.0
3.5
4.0 / 4.01 / 4.02
4.5


====================
2 Top X questions
====================

Q: I can't run PDOXDOS! I get
"Unexpected condition: GP 0000 AT PARADOX:28:1323 --
Leaving Paradox"

A: Too much RAM. Add -extk 16000 to the command-line.
    See [3.1]

Q: Is Paradox for DOS Y2K compliant?
A: Yes, though see Appendix A for a few "caveats".

To be compiled


====================
3 General Questions
====================

------------------------
 3.1 I can't run PDOXDOS! I get
 Unexpected condition: GP 0000 AT PARADOX:28:1323 -- 
Leaving Paradox
------------------------

Paradox, as a DOS program, uses a "286 extender" which
allows to address up to 16 Megs of memory. If you have 
more than that, the program thinks there's a problem with 
your machine and quits. You can force Paradox to use ONLY 
16 Megs of RAM by adding

  -extk 16000

to the command-line. That should allow it to run.

------------------------
 3.2 Is Paradox for DOS Y2K compliant?
------------------------

Yes, though there's a few caveats you need to know. See 
Appendix A.

------------------------
 3.3 Does Paradox for DOS run under Windows?
------------------------

It is recommended that you upgrade to at least 4.02, if 
not 4.5 to run it reliably under Windows. Older versions 
may have problems up to and including data corruption.


====================
4 Table Questions
====================

------------------------
 4.1 How do I repair a damaged table?
------------------------

Use the included TUTILITY.EXE program in the same 
directory.


====================
5 Forms and Reports Question
====================

To be compiled.

====================
6 PAL Questions
====================

To be compiled.

====================
7 Network and Multi-user Questions
====================

To be compiled.

====================
8 Misc. Questions
====================

To be compiled.

====================
9 Troubleshooting
====================

------------------------
 9.1 Command-line parameters
------------------------

See the Help entry of this name in the Paradox
Help. Note that Paradox is installed with "-b",
meaning that only one instance will run at a time.
However, you may actually run many instances of
Paradox simultaneously on the same machine. The only
restriction is that each is launched with a "-p"
parameter indicating a unique private subdirectory.


----END----

========================
Appendix A: Y2K and Paradox
========================

How will Paradox react to the year 2000? Will it still 
work? The short answer is, Yes. All versions of Paradox 
for Windows and Paradox for DOS are Y2K compliant in the 
sense that they store dates with all digits of the year. 
Note that we have not separated DOS and Windows systems 
here.

HOWEVER,  your application may NOT be Y2K compliant. It is
possible to write applications that will not function
properly in the 21st Century.

For those just arriving, here's the scoop on what Y2K
compliance means.

There are a number of issues, most of them nothing to do
with Paradox <g>.

When business computer systems were first written, dates
were stored not as four digits (1999), but as two (99). 
This was for a number of reasons: it saved space on 
primitive computers where saving two bytes per record was 
a saving worth making; but also, because the end of the 
century was a long way away. What this means is that 
ambiguity exists as to whether a date is a 20th or 21st 
century date.

So, the problems to be addressed for Y2K compliance are:

Hardware
Operating System
Application System
 (Paradox and BDE, the Borland Database Engine, (Windows))
 (Paradox and Paradox Engine, for DOS)
Application

First - your computer (hardware) must be Y2K compliant.
Here's a simple test - but first a warning:

Some computers have been known to crash and burn when 
their clocks roll over at midnight on the evening of 
December 31st 1999 with major, unrecoverable hard disk 
errors. Backup your system first before trying this. We 
take no responsibility for any damage done to your system 
trying this test.

Having said that, you might as well find out now, rather
than ruin your New Year<g>.

To test this, set the date to December 31st, 1999, and set
the time to 11:59pm. Watch what happens. If your computer,
after midnight, rolls over to Jan 1st 2000, then your
computer probably is okay. Now try restarting the 
computer. If your computer still shows the date to be 
1/1/2000, that's a good sign. More strenuous tests exist, 
and if you are in any doubt, you should consult an expert 
in the field.

Next, your operating system. Microsoft insists that Win95,
Win98, and WinNT4 are compliant. But see the Microsoft 
site http://www.microsoft.com for details.

Next, your application system. As has been stated, all
versions of Paradox store years as four digits (strictly
speaking, Paradox stores dates as type LongInt, a long
integer, assigning every day since the year dot a unique
number, and then converts this number into a 
[corresponding, user readable] date). But that's only half 
the story. Paradox's database functions are driven by the 
Borland Database Engine. All versions of BDE are 
compliant.

With caveats (see below).

But here's the catch. Your application itself may NOT be
compliant. There are a number of possible reasons for 
this. Here are three examples which apply mainly to 
Windows versions of Paradox:

1/ With PdoxDOS, a two-digit year is always assumed to be
in the 20th Century. This will STILL be true in the 21st
Century.

But things can go wrong behind the scenes, and this is
where the trouble really starts.

2/ Your system may have fields that appear to be dates, 
but are in fact (for example) alphanumeric. This would 
mean that your system stores 5th of May 1999 as a string 
"05/05/99", for example. You may not even be able to see 
it in your forms, as the form may adjust it to read 
"05/05/1999". Clearly, here is a Y2K ambiguity. It may be 
simple to fix (convert the field to type date, which in 
itself may be a mission), or it may be impossible without 
an entire rewrite. Why? Because a programmer who casts a 
date as type string in a table will assume in all code 
that the field in question is a string.

Consequently, to get the year from a date, the string will
be parsed for just the seventh and eighth characters (the
"9" and the "9", in "05/05/99").

This will not work properly if the field is converted to
type date. This is a classic Y2K situation.

3/ The Paradox engine operates very much like the BDE. You
are not forced to enter 4-digit years. Two-digit ones
default to the 20th century.

So, while Paradox is compliant, your application might not
be. It's a very difficult question to answer without 
seeing a lot of code.

--end of Paradox FAQ--


Paradox Community Newsgroups


 Feedback |  Paradox Day |  Who Uses Paradox |  I Use Paradox |  Downloads 


 The information provided on this Web site is not in any way sponsored or endorsed by Corel Corporation.
 Paradox is a registered trademark of Corel Corporation.


 Modified: 15 May 2003
 Terms of Use / Legal Disclaimer


 Copyright © 2001- 2003 Paradox Community. All rights reserved. 
 Company and product names are trademarks or registered trademarks of their respective companies. 
 Authors hold the copyrights to their own works. Please contact the author of any article for details.